Vibratory grinding mill



VIBRATORY GRINDING MILL 2 Sheets-Sheet 1 Filed May 24. 1965 IIIIIII'll/[I114 III!- INVENTORS:

Oct. 19, 1965 HElNZ-JOCHEM MAEDER ETAL 3,212,723

VIBRA'I'ORY GR INDING MILL 2 Sheets-Sheet 2 Filed May 24, 1963INVENTORS:

United States Patent 3,212,723 VIBRATORY GRINDING MILL Heinz-JochemMaeder, Cologne-Dellbruck, and Walter Biinger, Cologne-Kalk, Germany,assignors to Klockner Humboldt Deutz Aktiengesellschaft, Cologne- Deutz,Germany, a corporation of Germany Filed May 24, 1963, Ser. No. 282,962Claims priority, application Germany, June 2, 1962, K 46,907 3 Claims.(Cl. 241171) Our invention relates to a continuously operating grindingmill of the vibratory type having one or more grinder drums whichcontain a number of balls or other grinder bodies and which receive thematerial to be ground through an inlet near one axial end of each drumand discharge the material near the opposite end.

In the known mills of this type, the material is supplied through aninlet opening or duct located above the load, namely the mass of grinderbodies and material, contained in the drum. In such mills, clogging mayoccur at the inlet because the material, after being charged onto thegrinder bodies, is only gradually set in motion and drawn between thegrinder bodies.

Since nowadays such grinding mills operate at a relatively high fillingdegree, amounting for example to about 70% of the cross-sectional areain the drum, the free space remaining above the grinding bodies israther small and can rapidly become filled with material suppliedthrough the inlet. As soon as the space is filled, the grinding bodiesprogressively lose their freedom of motion. This also impairs thetransportation of the material in the axial direction, thus increasingthe amount of clogging and often requiring the material feeder device tobe shut off. Since clogging of the grinder drum extremely impedes thethrowing motion of the grinder balls, a prolonged period of time isneeded under such conditions for running the vibratory mill empty, thisbeing necessary before the mill can be refilled with material to beground.

It is an object of our invention to eliminate the abovementionedshortcomings and difficulties encountered with vibratory drum-typegrinding mills.

To this end, and in accordance with a feature of our invention, thematerial supply of a continuously operating vibratory mill is arrangedbelow the drum axis so that the material enters into the grinder drumbeneath the operating level of the grinding bodies in the direction ofmotion performed by the grinding bodies and/or by the material beingground.

According to another feature of our invention, the material supply ductof the feeder device extends from above laterally about part of the drumbody and has its inlet opening located in tangential relation to theperiphery of the drum body below the longitudinal axis of the drum.

According to another advantageous embodiment of the invention, thematerial supply duct of the feeder device is mounted laterally of adrum-cover plate at the materialinput side of the grinder drum, and theinlet opening extends in the cover plate and is elongated in a directioninclined to the longitudinal center plane of the drum. In this case thesupply of material is substantially in the general travel direction ofthe material being ground in the drum.

According to a further feature of the invention, a removable lid isplaced upon the lower end of the supply duct for the material to permittaking specimens of the supplied material out of the inlet duct.

The above-mentioned and other objects, advantages and features of ourinvention, said features being set forth with particularity in theclaims annexed hereto. will be apparent from and will be described in,the fol- 3,212,723 Patented Oct. 19, 1965 lowing with reference toembodiments of vibratory grinding mills according to the inventionillustrated by way of example on the accompanying drawings in which:

FIG. 1 is a lateral view of a vibratory mill comprising two grinderdrums, the supporting and mounting structure being omitted.

FIG. 2 is a longitudinal section through the vertical center plane ofpart of the upper drum near the materialinlet side of the mill shown inFIG. 1.

FIG. 3 is a part-sectional front view upon the grinder drum according toFIG. 2.

FIG. 4 is a front view onto the inlet side of a grinder drum accordingto another embodiment of the invention.

FIG. 5 is a lateral view of part of the grinder drum shown in FIG. 4;and

FIG. 6 shows schematically a complete vibratory mill according to FIGS.1, 2 and 3.

The vibratory mill shown in FIGS. 1, 2. 3 and 6 comprises twocylindrical grinder drums l and 2, which are horizontally arranged oneabove the other in symmetrical relation to the drive shaft 10 of themachine. The upper drum 1 is provided with an inlet duct 3 for supplyingthe material 12 to be ground. Both drums contain a quantity of grinderbodies, such as hard balls, which during vibration are subjected tothrowing motion in order to grind the material. The material passes fromthe inlet side of the upper drum 1 to the opposite side and thencethrough a corrugated hose 8 into the lower grinder drum 2. In drum 2 thematerial is subjected to further grinding while traveling to the leftand through a screening partition to an outlet 9.

The two drums l and 2 are rigidly connected with each other by twobridge members 15 which carry respective bearings 16 for the machineshaft 10. The bridge members are rigidly joined with two lateralsupports 6 seated on respective spring members 18 preferably consistingof rubber bodies. The springs 18 are supported on rigid standards 19secured to the foundation of the plant. By virtue of this mounting, therigid assembly comprising the two grinder drums is capable of swingingmotion in transversal planes parallel to the plane of illustration inFIGS. 3 and 6. The shaft 10 carries unbalance weights 11 and is drivenfrom a stationarily mounted motor (not shown). Due to the rotation ofthe unbalance weights 11, the drum structure receives pulses which causeit to perform a substantially circulating vibration in planes transverseto the drum axes. It will be understood that the particular unbalancedrive is not essential to the invention proper and may be substituted byother vibratory drives such as those operating with a rotating crankcoupled with the vibratory drum system by means of a spring.

The grinder balls in each drum occupy only part of the internal drumspace and thus approximately define a load level in each drum. Duringoperation of the mill, the grinder balls in each drum perform a throwingmotion thus imposing a comminuting action by impact and friction uponthe material to be ground.

While in the known vibratory drum or tube mills, the feeder conduit isjoined with the top of the drum to supply the material upon thejust-rnentioned level, the duct 3 in the vibratory mill according toFIGS. 1 to 3 and 6 extends from above laterally about part of the drumperiphery so that the feeder inlet opening of the drum, through whichthe duct 3 communicates with the interior of the drum, extendstangentially to the drum periphery below the longitudinal axis of thedrum. This permits supplying the material in the throw direction of thegrinding bodies or balls and thereby affords a continuous supply ofmaterial without danger of clogging the drum.

It is of advantage to provide the lower end of the sup ply duct 3 with acover or lid 6 which can be turned to open position or fully removed sothat specimens of the material to be ground can be taken out at any timefrom the material passing through duct 3 and into the drum.

In the embodiment according to FIGS. 4 and 5, the duct 4 of the materialfeeder device is arranged beside the axial end, namely in front of thecover plate 7 at the feeder side of the drum 1, and the inlet opening 4is located in the cover plate 7 and is elongated in an inclineddirection with respect to the longitudinal vertical center plane of thedrum. In this case the material enters into the drum generally in thetraveling direction of the material 12 being ground, that is in thedirection from the cover plate 7 at the feeder side to the opposite endof the drum where the drum outlet and the corrugated hose 8 is located.

The supply duct 4 receives the material from a vertical feeder conduit 5which is rigidly fastened, for example by brackets or flanges (notshown), to the cover plate 7 of the drum. The lower end of the feederconduit 5 is closed by a cover 6 which can be turned open or removed inorder to permit specimens of the material to be taken from time to time.

As is the case with a tangential supply of the vibratory mill withmaterial to be ground (FIGS. 1 to 3 and 6), the lateral supply throughan opening in the cover plate 7 of the drum (FIGS. 4, 5) also affords acontinuous supply of material without danger of clogging the mill.

The tangential as well as the axially lateral supply of the material tobe ground also otter the advantage of feeding the material into the millbelow the level of the grinding bodies, namely either in the directionof motion of the grinder bodies (tangential supply) or in the traveldirection of the material being ground (axially lateral supply of thematerial). In both cases, exemplified by the above-described embodimentsof the invention, the material to be ground enters only into theinterspaces between the grinding bodies or balls as they pass by theinlet opening. Thus the material is promptly removed from the inletopening in a manner that virtually amounts to a dosage-forming action.This promotes the prevention of clogging.

By virtue of the tangential or lateral supply of the material, thismaterial can be fed into the drum at the side at which the grinderbodies perform a downward motion. This secures a continuous feedingaction upon the material to be ground, thereby also contributing toreliable prevention of clogging.

To those skilled in the art, it will be obvious upon a study of thisdisclosure that vibratory grinding mills according to the invention canbe modified in various respects and can be given embodiments other thanparticularly illustrated and described herein, without departing fromthe essential features of our invention and within the scope of theclaims annexed hereto.

We claim:

1. A continuously operable vibratory grinding mill, comprising at leastone vibratingly mounted grinder drum whose axis extends substantiallyhorizontally and which contains grinder bodies up to an approximatelevel, said drum having near one end a material inlet opening locatedsubstantially below said level, and having an outlet near the other end,vibratory drive means connected with said drum for vibrating said drumwhereby motion relative to the drum is imparted to said grinder bodiesin a direction transverse to the drum axis and the material is caused totravel in the direction from said inlet opening to said outlet, and aduct for supplying material communicating with said drum through saidinlet opening below said level and extending in one of said twodirections at said opening, said material supply duct having adownwardly extending portion ahead of said inlet opening, and aremovable cover on said duct portion for taking specimens of thematerial being supplied.

2. A continuously operable vibratory grinding mill, comprising at leastone elongated grinder drum whose axis extends substantiallyhorizontally, said drum having an elastic mounting for circulatorytransverse vibration and containing grinder bodies partially filling thedrum, said drum having near one end an inlet opening for material to beground and having an outlet near the other end, vibratory drive meansconnected with said drum for vibrating said drum whereby motion relativeto the drum is imparted to said grinder bodies in a direction transverseto the drum axis and the material is caused to travel in the directionfrom said inlet opening to said outlet, said inlet opening being locatedsubstantially below the drum axis, and a duct for supplying materialcommunicating with said drum through said inlet opening and extendingfrom above laterally of the drum and thence substantially in atangential direction to said inlet opening for feeding the material tothe drum in the moving direction of said bodies at said inlet opening.

3. A continuously operable vibratory grinding mill, comprising at leastone vibratingly mounted grinder drum whose axis extends substantiallyhorizontally and which contains grinder bodies partially filling thedrum, said drum having a cover plate on one axial end and having in saidcover plate an inlet opening for material to be ground and having anoutlet near the other end, vibratory drive means connected with saiddrum for vibrating said drum whereby motion relative to the drum isimparted to said grinder bodies in a direction transverse to the drumaxis and the material is caused to travel in the direction from saidinlet opening to said outlet, said inlet opening being locatedsubstantially below the drum axis and extending in a direction inclinedto the vertical ccnterplane of the drum and a duct for supplyingmaterial communicating with said drum through said inlet opening andextending from above axially beside said cover plate, whereby thematerial enters into the drum substantially in the direction of travelof the material through the drum.

References Cited by the Examiner UNITED STATES PATENTS 1,115,531 11/14Hardinge 241-175 2,468,515 4/49 Robinson 241l75 X FOREIGN PATENTS1,105,258 4/61 Germany.

ROBERT C. RIORDON, Primary Examiner.

J. SPENCER OVERHOLSER, Examiner.

1. A CONTINUOUSLY OPERABLE VIBRATORY GRINDING MILL, COMPRISING AT LEASTONE VIBRATINGLY MOUNTED GRINDER DRUM WHOSE AXIS EXTENDS SUBSTANTIALLYHORIZONTALLY AND WHICH CONTAINS GRINDER BODIES UP TO AN APPROXIMATELEVEL, SAID DRUM HAVING NEAR ONE END A MATERIAL INLET OPENING LOCATEDSUBSTANTIALLY BELOW SAID LEVEL, AND HAVING AN OUTLET NEAR THE OTHER END,VIBRATORY DRIVE M EANS CONNECTED WITH SAID DRUM FOR VIBRATORY DRIVEMEANS CONNECTED RELATIVE TO THE DRUM IS IMPARTED TO SAID GRINDER BODIESIN A DIRECTION TRANSVERSE TO THE DRUM AXIS AND THE MATERIAL IS CAUSED TOTRAVEL IN THE DIRECTION FROM SAID INLET OPENING TO SAID OUTLET, AND ADUCT FOR SUPPLYING MATERIAL COMMUNICATING WITH SAID DRUM THROUGH SAIDINLET OPENING BELOW SAID LEVEL AND EXTENDING IN ONE OF SAID TWODIRECTIONS AT SAID OPENING, SAID MATERIAL SUPPLY DUCT HAVING ADOWNWARDLY EXTENDING PORTION AHEAD OF SAID INLET OPENING, AND AREMOVABLE COVER ON SAID DUCT PORTION FOR TAKING SPECIMENS OF THEMATERIAL BEING SUPPLIED.